Achiral two-dimensional perovskite exhibiting giant circularly polarized luminescence and circular photogalvanic effect.

W. U. Jeong, S.-M. Lee, T. J. Jeong, G. B. Lee, E. Choi, M. Lyu, P. Bernhardt, R. G. Elliman, Y. Ryu, J.-H. Yun, S. Kim, S.-H. Choi.

Composition-tunable valley polarization in monolayer Mo1-xWxS2 alloys

Current Applied Physics, 84, 12–18

We report a systematic study of excitonic resonance and valley polarization in monolayer Mo1-xWxS2 alloys with compositions x = 0, 0.4, 0.6, and 1.0. Monolayers prepared by mechanical exfoliation were characterized by microscopy, Raman, and X-ray photoelectron spectroscopy.

W. U. Jeong, J. B. Ahn, T. J. Jeong, Y. Ryu, S. Kim

Temperature-driven crossover of excitonic radiative channels and valley polarization in monolayer WS₂

Journal of Alloys and Compounds, 1060, 187278

We perform helicity-resolved photoluminescence spectroscopy on unencapsulated exfoliated monolayer WS₂ on SiO₂/Si, a technologically relevant baseline platform for scalable devices, over a wide temperature range from 80 to 360 K, using both co- and cross-circular polarization detection.

W. U. Jeong, J. Bin Ahn, T. J. Jeong, G. Bin Lee, S. Kim, S.-H. Choi

Experimental manifestation of topological lifshitz transition by observing thickness-dependent shift of plasma frequency in topological semimetals.

Materials Today Physics, 60, 101981

In this study, we observe a topological LT in epitaxial thin films of Bi0.96Sb0.04 without external excitations, where the TSM characteristics are retained throughout the transition.

M. S. Kim, C. W. Jang, W. U. Jeong, S. Kim, R. G. Elliman, E. Hwang, J. S. Lee, S.-H. Choi